Mickey7Kid gave a reasonable answer without all the math bullshit
lugalWhy would you ask “How is this possible” when you expect the answer to be “it’s not”?
Because they spent an entire math class period earlier that week explaining to the students what "reasonableness" was going to mean on their next math test, and in the context of (I'm guessing 3rd or 4th grade) arithmetic the important thing they're trying to teach is that 5/6 is a larger fraction than 4/6. I agree that the question could be worded better (change the last two sentences to "Marty says he ate more pizza. Is this possible?") but I strongly suspect that the missing context from their class - or maybe even at the beginning of the test - explains enough to get the answer the teacher was looking for here.
Yes, one kid starting with a larger pizza changes the situation, but fundamentally that's an algebra question, not a "learning fractions" question.
I agree that the idea they were teaching was “is it reasonable for 4/6 to be larger than 5/6”, but it was too sloppy to be in a word problem with cultural context. Sometimes if you’re the teacher and a kid stumbles onto a loophole this big, you have to take the L and update your materials for the next year. Just add, “Marty and Luis ordered small pizzas at Joe’s,” and this goes away. This feels like the question writer had been in a groove with drafting more abstract problem sets, and didn’t do a good job when shifting gears into the word problem section.